Rheumatoid hyperviscosity: analysis of a patient with intermediate complexes that block other autoantibodies and a review of the literature

To report a patient whose rheumatoid arthritis presented withhyperviscosity syndrome, analyze this patient's rheumatoid factor, and review the previously reported patients. Immunofluorescence for antinuclear antibodies, double immunodiffusion,enzyme-linked immunosorbent assay, and size exclusion chromatography were used before and after plasmapheresis to study the patient's rheumatoid hyperviscosity. A systematic Medline search of rheumatic illnesses, hyperviscosity, and polyclonal gammopathy and references in identified papers was used to identify previously reported patients. Similar to several previous patients, this patient's sera contained bothIgG and IgM rheumatoid factor and abundant intermediate complexes. Other autoantibodies, either from the patient or from other patients, were masked by rheumatoid factor or intermediate complexes from the reported patient's sera. Rheumatic hyperviscosity is seen uncommonly, being reported in only 18 patients with rheumatoid arthritis and nine with other rheumatic illnesses. There are two mechanisms by which rheumatoid factor can leadto hyperviscosity, both of which require large amounts of rheumatoid factor. Rheumatoid hyperviscosity must be recognized because this life-threatening syndrome usually can be successfully treated with plasmapheresis acutely and immunosuppressives for long-term control.